3R Regeneration is considered a key-function for the future long-haul all-optical networks. It preserves data quality and allows for improved transmission distances [1], thus enhancing transparency, scalability, and flexibility of optical networks [2]. Moreover, wavelength conversion is important to avoid wavelength blocking at nodes of the optical networks [2]. In addition, clock recovery with low phase noise yielding rms jitter is required to achieve high bit-rate transmission [3]. Conventional 3R regeneration techniques require two cascaded stages, one to perform timing extraction in order to recover the clock and the other to function as a nonlinear decision element [4]. (a) The measured EAM transmission versus input average pump power at reverse bias. (b) The measured transmission window FWHM at different input average powers and reverse biases. Measurements are made at 1 GHz, 1545 nm, using a 3.3-ps pulsewidth (a) Schematic configuration of the counterpropagation. (b) The measured peak power of the EAM two outputs versus delay, in this case, with equal inputs power (7.4 dBm), at 1 GHz. (c) Generated error signal at the output of the balance detector (Bandwidth = 100 kHz) with an open feedback loop,
Abstract:
The authors demonstrate a technique that utilizes a single electro-absorption modulator (EAM) to perform simultaneous all-optical timing extraction, reshaping, and wavele...Show MoreMetadata
Abstract:
The authors demonstrate a technique that utilizes a single electro-absorption modulator (EAM) to perform simultaneous all-optical timing extraction, reshaping, and wavelength conversion. The extracted timing is used to generate an error signal that is used to recover the optical clock. The same EAM is used to encode the incoming data onto the retimed clock pulses in order to perform 3R regeneration and wavelength conversion. The system performance was tested using a 2/sup 31/-1 pseudorandom binary sequence (PRBS) data running at 10 Gb/s with a 3.3-ps pulsewidth. The input data was degraded by adding a 500-kHz timing jitter and reducing the optical signal-to-noise ratio (SNR) to 18 dB. The 3R regenerated data showed a 4.7-dB improvement in power penalty and 20-dB improvement in optical SNR. The calculated timing jitter of the recovered clock is less than 230 fs.
Published in: IEEE Photonics Technology Letters ( Volume: 14, Issue: 9, September 2002)